I have found in Worldcat a reference to this book by Simon Dubnow : Fun "zsargon" tsu Yidish, with the mentions : "Éditeur : Amherst : National Yiddish Book Center, " and "Collection : Steven Spielberg digital Yiddish library, no. 12249". But I can't find it, even when trying different spellings for "zsargon" (that should be "zhargon", I think, following YIVO transliteration rules). And even when browsing all the works of S. Dubnow.
The page in Worldcat is : http://www.worldcat.org/oclc/155849086
Can anyone help?